From: Pali Rohár pali@kernel.org
[ Upstream commit f122121796f91168d0894c2710b8dd71330a34f8 ]
Function CIFSSMBSetPathInfo() is not supported by non-NT servers and returns error. Fallback code via open filehandle and CIFSSMBSetFileInfo() does not work neither because CIFS_open() works also only on NT server.
Therefore currently the whole smb_set_file_info() function as a SMB1 callback for the ->set_file_info() does not work with older non-NT SMB servers, like Win9x and others.
This change implements fallback code in smb_set_file_info() which will works with any server and allows to change time values and also to set or clear read-only attributes.
To make existing fallback code via CIFSSMBSetFileInfo() working with also non-NT servers, it is needed to change open function from CIFS_open() (which is NT specific) to cifs_open_file() which works with any server (this is just a open wrapper function which choose the correct open function supported by the server).
CIFSSMBSetFileInfo() is working also on non-NT servers, but zero time values are not treated specially. So first it is needed to fill all time values if some of them are missing, via cifs_query_path_info() call.
There is another issue, opening file in write-mode (needed for changing attributes) is not possible when the file has read-only attribute set. The only option how to clear read-only attribute is via SMB_COM_SETATTR command. And opening directory is not possible neither and here the SMB_COM_SETATTR command is the only option how to change attributes. And CIFSSMBSetFileInfo() does not honor setting read-only attribute, so for setting is also needed to use SMB_COM_SETATTR command.
Existing code in cifs_query_path_info() is already using SMB_COM_GETATTR as a fallback code path (function SMBQueryInformation()), so introduce a new function SMBSetInformation which will implement SMB_COM_SETATTR command.
My testing showed that Windows XP SMB1 client is also using SMB_COM_SETATTR command for setting or clearing read-only attribute against non-NT server. So this can prove that this is the correct way how to do it.
With this change it is possible set all 4 time values and all attributes, including clearing and setting read-only bit on non-NT SMB servers. Tested against Win98 SMB1 server.
This change fixes "touch" command which was failing when called on existing file. And fixes also "chmod +w" and "chmod -w" commands which were also failing (as they are changing read-only attribute).
Note that this change depends on following change "cifs: Improve cifs_query_path_info() and cifs_query_file_info()" as it require to query all 4 time attribute values.
Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifspdu.h | 5 +- fs/smb/client/cifsproto.h | 4 ++ fs/smb/client/cifssmb.c | 57 +++++++++++++++++++ fs/smb/client/smb1ops.c | 112 +++++++++++++++++++++++++++++++++++--- 4 files changed, 166 insertions(+), 12 deletions(-)
diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h index 48d0d6f439cf4..cf9ca7e49b8bc 100644 --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/cifspdu.h @@ -1266,10 +1266,9 @@ typedef struct smb_com_query_information_rsp { typedef struct smb_com_setattr_req { struct smb_hdr hdr; /* wct = 8 */ __le16 attr; - __le16 time_low; - __le16 time_high; + __le32 last_write_time; __le16 reserved[5]; /* must be zero */ - __u16 ByteCount; + __le16 ByteCount; __u8 BufferFormat; /* 4 = ASCII */ unsigned char fileName[]; } __attribute__((packed)) SETATTR_REQ; diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h index 278092a15f890..cc3c0f08d0365 100644 --- a/fs/smb/client/cifsproto.h +++ b/fs/smb/client/cifsproto.h @@ -392,6 +392,10 @@ extern int CIFSSMBQFSUnixInfo(const unsigned int xid, struct cifs_tcon *tcon); extern int CIFSSMBQFSPosixInfo(const unsigned int xid, struct cifs_tcon *tcon, struct kstatfs *FSData);
+extern int SMBSetInformation(const unsigned int xid, struct cifs_tcon *tcon, + const char *fileName, __le32 attributes, __le64 write_time, + const struct nls_table *nls_codepage, + struct cifs_sb_info *cifs_sb); extern int CIFSSMBSetPathInfo(const unsigned int xid, struct cifs_tcon *tcon, const char *fileName, const FILE_BASIC_INFO *data, const struct nls_table *nls_codepage, diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 4fc9485c5d91a..da8b28f63fcb5 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -5150,6 +5150,63 @@ CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon, return rc; }
+int +SMBSetInformation(const unsigned int xid, struct cifs_tcon *tcon, + const char *fileName, __le32 attributes, __le64 write_time, + const struct nls_table *nls_codepage, + struct cifs_sb_info *cifs_sb) +{ + SETATTR_REQ *pSMB; + SETATTR_RSP *pSMBr; + struct timespec64 ts; + int bytes_returned; + int name_len; + int rc; + + cifs_dbg(FYI, "In %s path %s\n", __func__, fileName); + +retry: + rc = smb_init(SMB_COM_SETATTR, 8, tcon, (void **) &pSMB, + (void **) &pSMBr); + if (rc) + return rc; + + if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) { + name_len = + cifsConvertToUTF16((__le16 *) pSMB->fileName, + fileName, PATH_MAX, nls_codepage, + cifs_remap(cifs_sb)); + name_len++; /* trailing null */ + name_len *= 2; + } else { + name_len = copy_path_name(pSMB->fileName, fileName); + } + /* Only few attributes can be set by this command, others are not accepted by Win9x. */ + pSMB->attr = cpu_to_le16(le32_to_cpu(attributes) & + (ATTR_READONLY | ATTR_HIDDEN | ATTR_SYSTEM | ATTR_ARCHIVE)); + /* Zero write time value (in both NT and SETATTR formats) means to not change it. */ + if (le64_to_cpu(write_time) != 0) { + ts = cifs_NTtimeToUnix(write_time); + pSMB->last_write_time = cpu_to_le32(ts.tv_sec); + } + pSMB->BufferFormat = 0x04; + name_len++; /* account for buffer type byte */ + inc_rfc1001_len(pSMB, (__u16)name_len); + pSMB->ByteCount = cpu_to_le16(name_len); + + rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB, + (struct smb_hdr *) pSMBr, &bytes_returned, 0); + if (rc) + cifs_dbg(FYI, "Send error in %s = %d\n", __func__, rc); + + cifs_buf_release(pSMB); + + if (rc == -EAGAIN) + goto retry; + + return rc; +} + /* Some legacy servers such as NT4 require that the file times be set on an open handle, rather than by pathname - this is awkward due to potential access conflicts on the open, but it is unavoidable for these diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c index bf301db3c0784..f9acd25adcad9 100644 --- a/fs/smb/client/smb1ops.c +++ b/fs/smb/client/smb1ops.c @@ -901,6 +901,9 @@ smb_set_file_info(struct inode *inode, const char *full_path, struct cifs_fid fid; struct cifs_open_parms oparms; struct cifsFileInfo *open_file; + FILE_BASIC_INFO new_buf; + struct cifs_open_info_data query_data; + __le64 write_time = buf->LastWriteTime; struct cifsInodeInfo *cinode = CIFS_I(inode); struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); struct tcon_link *tlink = NULL; @@ -908,20 +911,58 @@ smb_set_file_info(struct inode *inode, const char *full_path,
/* if the file is already open for write, just use that fileid */ open_file = find_writable_file(cinode, FIND_WR_FSUID_ONLY); + if (open_file) { fid.netfid = open_file->fid.netfid; netpid = open_file->pid; tcon = tlink_tcon(open_file->tlink); - goto set_via_filehandle; + } else { + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + tlink = NULL; + goto out; + } + tcon = tlink_tcon(tlink); }
- tlink = cifs_sb_tlink(cifs_sb); - if (IS_ERR(tlink)) { - rc = PTR_ERR(tlink); - tlink = NULL; - goto out; + /* + * Non-NT servers interprets zero time value in SMB_SET_FILE_BASIC_INFO + * over TRANS2_SET_FILE_INFORMATION as a valid time value. NT servers + * interprets zero time value as do not change existing value on server. + * API of ->set_file_info() callback expects that zero time value has + * the NT meaning - do not change. Therefore if server is non-NT and + * some time values in "buf" are zero, then fetch missing time values. + */ + if (!(tcon->ses->capabilities & CAP_NT_SMBS) && + (!buf->CreationTime || !buf->LastAccessTime || + !buf->LastWriteTime || !buf->ChangeTime)) { + rc = cifs_query_path_info(xid, tcon, cifs_sb, full_path, &query_data); + if (rc) { + if (open_file) { + cifsFileInfo_put(open_file); + open_file = NULL; + } + goto out; + } + /* + * Original write_time from buf->LastWriteTime is preserved + * as SMBSetInformation() interprets zero as do not change. + */ + new_buf = *buf; + buf = &new_buf; + if (!buf->CreationTime) + buf->CreationTime = query_data.fi.CreationTime; + if (!buf->LastAccessTime) + buf->LastAccessTime = query_data.fi.LastAccessTime; + if (!buf->LastWriteTime) + buf->LastWriteTime = query_data.fi.LastWriteTime; + if (!buf->ChangeTime) + buf->ChangeTime = query_data.fi.ChangeTime; } - tcon = tlink_tcon(tlink); + + if (open_file) + goto set_via_filehandle;
rc = CIFSSMBSetPathInfo(xid, tcon, full_path, buf, cifs_sb->local_nls, cifs_sb); @@ -942,8 +983,45 @@ smb_set_file_info(struct inode *inode, const char *full_path, .fid = &fid, };
- cifs_dbg(FYI, "calling SetFileInfo since SetPathInfo for times not supported by this server\n"); - rc = CIFS_open(xid, &oparms, &oplock, NULL); + if (S_ISDIR(inode->i_mode) && !(tcon->ses->capabilities & CAP_NT_SMBS)) { + /* Opening directory path is not possible on non-NT servers. */ + rc = -EOPNOTSUPP; + } else { + /* + * Use cifs_open_file() instead of CIFS_open() as the + * cifs_open_file() selects the correct function which + * works also on non-NT servers. + */ + rc = cifs_open_file(xid, &oparms, &oplock, NULL); + /* + * Opening path for writing on non-NT servers is not + * possible when the read-only attribute is already set. + * Non-NT server in this case returns -EACCES. For those + * servers the only possible way how to clear the read-only + * bit is via SMB_COM_SETATTR command. + */ + if (rc == -EACCES && + (cinode->cifsAttrs & ATTR_READONLY) && + le32_to_cpu(buf->Attributes) != 0 && /* 0 = do not change attrs */ + !(le32_to_cpu(buf->Attributes) & ATTR_READONLY) && + !(tcon->ses->capabilities & CAP_NT_SMBS)) + rc = -EOPNOTSUPP; + } + + /* Fallback to SMB_COM_SETATTR command when absolutelty needed. */ + if (rc == -EOPNOTSUPP) { + cifs_dbg(FYI, "calling SetInformation since SetPathInfo for attrs/times not supported by this server\n"); + rc = SMBSetInformation(xid, tcon, full_path, + buf->Attributes != 0 ? buf->Attributes : cpu_to_le32(cinode->cifsAttrs), + write_time, + cifs_sb->local_nls, cifs_sb); + if (rc == 0) + cinode->cifsAttrs = le32_to_cpu(buf->Attributes); + else + rc = -EACCES; + goto out; + } + if (rc != 0) { if (rc == -EIO) rc = -EINVAL; @@ -951,6 +1029,7 @@ smb_set_file_info(struct inode *inode, const char *full_path, }
netpid = current->tgid; + cifs_dbg(FYI, "calling SetFileInfo since SetPathInfo for attrs/times not supported by this server\n");
set_via_filehandle: rc = CIFSSMBSetFileInfo(xid, tcon, buf, fid.netfid, netpid); @@ -961,6 +1040,21 @@ smb_set_file_info(struct inode *inode, const char *full_path, CIFSSMBClose(xid, tcon, fid.netfid); else cifsFileInfo_put(open_file); + + /* + * Setting the read-only bit is not honered on non-NT servers when done + * via open-semantics. So for setting it, use SMB_COM_SETATTR command. + * This command works only after the file is closed, so use it only when + * operation was called without the filehandle. + */ + if (open_file == NULL && + !(tcon->ses->capabilities & CAP_NT_SMBS) && + le32_to_cpu(buf->Attributes) & ATTR_READONLY) { + SMBSetInformation(xid, tcon, full_path, + buf->Attributes, + 0 /* do not change write time */, + cifs_sb->local_nls, cifs_sb); + } out: if (tlink != NULL) cifs_put_tlink(tlink);